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Updated: Jun 27, 2026
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Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
Changes in control of saccades during gain adaptation
Vincent Ethier1, David S Zee, Reza Shadmehr
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
Summary
The brain adapts eye movements differently depending on the error. Gain-down adaptation alters saccade trajectories via internal feedback, while gain-up adaptation remaps the target. Both minimize motor costs.
Area of Science:
- Neuroscience
- Motor Control
- Ophthalmology
Background:
- Saccadic adaptation is a key mechanism for maintaining accurate vision.
- The underlying neural processes, whether target remapping or internal feedback, remain debated.
Purpose of the Study:
- To investigate the distinct neural mechanisms of saccadic adaptation in gain-down and gain-up paradigms.
- To determine if adaptation involves altering motor commands (target remapping) or correcting them midflight (internal feedback).
Main Methods:
- Participants underwent short-term saccadic adaptation protocols (gain-down and gain-up).
- Saccade trajectories, peak velocities, accelerations, decelerations, and durations were analyzed.
- Computational simulations were used to model motor costs.
Main Results:
- Gain-down adaptation altered saccade trajectories, reducing peak velocities and accelerations, consistent with internal feedback.
- Gain-up adaptation produced larger amplitude saccades with unchanged trajectories, suggesting target remapping.
- Simulations confirmed that both adaptations minimized motor costs.
Conclusions:
- Saccadic adaptation employs distinct mechanisms: internal feedback for gain-down and target remapping for gain-up.
- These findings elucidate the flexibility of the motor system in error correction.
- Understanding these mechanisms is crucial for visual-motor rehabilitation.
